Cooling tower



Aug. 5, 1941. r s c. COEY COOLING TOWER Original Filed Dec. 2a. 1936 2 Sheets-Sheet 1 pAug- 1941. s. c. COEY 2,251,261

000mm TOWER ori inal Filed bee. 2a, 1936 2 Sheets Sheet 2 Patented Aug. 1941-. I

STATE cooLrNG rowan smart c. (Joey, Glen mar s. 1.

Original application Dece mber 2a, 1936, Serial mt.

117,996. Divided and this application October 8, 1937, Serial No. 168,103

3 Claims. (01. 257-44) This invention relates to liquid cooling towers and more particularly to such towers cooled by forced air currents as distinguished from natural draft.

It is a general-object of the present invention to provide a novel and improved type of liquid cooling tower.

More particularly it is an object of the invention to provide a multi-stage liquid cooling tower using forced air circulation.

An important feature of the present invention, in addition to the structural features which permit of low cost and compact size, resides in the use of multi-stage cooling in which the air flows countercurrent to the liquid and all of it passes in successive stages through the liquid, whereby the total amount of air required to be circulated to produce a given temperature change in the liquid is, substantially 50% less than that required in single stage cooling, obviously effecting material savings in size and operating expense of .the tower.

Another important feature of the tower of the present invention consists in the provision of means for using an air circulating device of the soscalled "squirrel cage type and through which all ofjthe air used by the tower passes radiallyv andwhich is preferably arranged interstage, producing at least one stage of suction cooling and one or more stages of pressure cooling. This absolutely ensures against the formation of ice on the blades of the rotor in the coldest weather.

A further feature of the invention resides in I taken substantially on line 1-2 of Figure 1; and r the provision pf a multi-stage' forced draftcooling towerin whic'h'all of the air passes at substantially right angles to the falling liquid in each stage.

Other and further features and objects of the invention will bemore apparent to those skilled in the art upon a consideration of the accompanying drawings and following specification, wherein is disclosed exemplary embodiments of the invention, with the understanding, however,

that various changes may be made therein, such' for instance as in the number and disposition of the stages, in the arrangement and structural features of the liquid baffles, and any other points of construction and arrangement of parts such as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawings:

Figure 1 is a vertical central section partially in elevation and partially schematlcal of a coolpacity. It is low in height to reduce the pump-' ing tower constructed according tothe presentv invention;

Figure 2 is a horizontal'cross sectional view Figure 3 is a horizontal cross sectional view taken substantially on line 3-3 of Figure 1.

With the increase in the use of refrigeration and room cooling machinery and the increase in power of engines, there have been added demands for increased capacity cooling towers for handling the cooling liquid, condenser water and the like. The added demands placed on the municipal water supply systems by such apparatus. where cooling and re-use .of the water is not resorted to, has brought about legislation in many cities limiting or entirely prohibiting the use of water for cooling purposes where it is not cooled and re-used.

Heretofore cooling towers of various types have been used with more or less success, but previous types have been open to various objections. The naturaldraft towers are seriously limited in their cooling capacity on still days, so that they must be built of adequate size to produce all of the required cooling on just such days, which makes them extremely cumbersome and the weight becomes a critical factor since they are usually and heavy. Most previous types of cooling towers have been subject to the very serious objection of spray dissemination, sometimes resulting in law suits against their users by owners .of adjacent property. Then too, the amount of water lost by spraying is 'a very considerable item and adds that much to the cost of operation of the apparatus. Towers which are large, particularly in height,wsometimes reach above the level allowed for buildings where certain restrictions are placed thereon and increased height also means increased cost of operation because of the additional pumping head. V

The ower of the present invention can be made of less than half the volume of heretofore known cooling towers of the forced draft type and probably less than ,4; to A of the volume of 'a natural draft cooling tower of the same caing head, is compact and sightly, requires little power for operation, permits of a greater cooling through the water.

range than heretofore available and is withal less costly than prior forms of towers.

The improved results attained with the tower of the present invention are essentially derived from the multi-stage operation wherein the same air passes counter-current a number of times This makes use of the air to its fullest extent. To illustrate the application of this principle it may be mentioned that in computing the results to be attained by a single stage cooling tower where it was desired to cool 800 gallons per minute of water from 100 F. to 80 F. with an atmosphere wet bulb temperature of 75 F. it was found that on the single pass principle it was necessary to use a tower delivering 255,000 cubic feet of air per minute to accomplish the result. With a threestage cascade tower the same result could be stages would be as follows:

sponding to the tops of the walls I 08 is closed by a partition I I0.

The air for evaporating some of the water or liquid is drawn in through openings III in the outside casing and thence transversely inwardly through the lower bank or group of coolers indicated generally by the letter A. The air is then drawn into the inlet I I2 of the air circulating means Hi3 which may be of the squirrel cage type and is discharged outwardly and transversely through the second bank of coolers indicated by reference letter B. Suitable partitions H4, and IIS are providedto keep the inlet and outlet currents of air separated. The interior of the tower just above the fan is suitably closed by partition IIB which carries a bearing II! for the fan. The fan shai t lIB projects downwardly through partition 0 and at its lower end is supported by a bearing H0. The shaft is suitably driven from a motor I20 by the belt and pulley drive I2I.

drawings to which reference should now be had for a full understanding of the invention. The tower is designed to be supported on any suitable structure, for instance, above a roof. Broadly, the tower consists of superposed groups or. banks of evaporative coolers, each cooler comprising a plurality of superposed finned pipes extending between headers. Liquid to be,cooled is circulated through the pipes and other liquid is distributed over the top pipes of the coolers whereby it falls from pipe to pipe and on the fins, cooling being effected by passing air through the coolers evaporating some of the liquid. The pipes constitute bailles, the fall of the liquid forming the curtain being interrupted periodically by the same.

Referring to Figs. 1, 2 and 3, the evaporative coolers or heat exchangers are shown as comprising vertical end headers I00 connected by vertically spaced horizontal pipes IOI carrying vertical fins M2 in the form of thin sheets having holes therethrough for the pipes. At the top of each cooler there is a channel or liquid feed trough I03 suitably secured to the headers and formed with a lengthwise slot I04 in its bottom wall for distributing liquid over the pipes and fins.

These coolers are arranged to form a hollow tower or chimney, polygonal in cross section. As shown, four coolers are disposed at each pass or level forming a substantially closed four-sided figure, and as seen from Fig. 1, the tower has a four banks or horizontal groups of coolers ar- Air temp.wetbulb B. t. u. removed Pass Water Temp. Water in Per cu. it. In Out n. Total Gallons Degree: Degrees Degrees Degrees per min. 1.. s3 so 100 800 0.555 66,600 7s 83 c0 84 800 0.328 40,000 a ,15 7a 84 so 800 0.212 26,000 Net overall 75 80 80 800 133,200

structurally the tower is extremely simple and The partitions H6 and I22 are provided with compact as illustrated in the accompanying 5 vertical walls I23 and I24, respectively, thus forming a receptacle or trough for collecting water as will be presently described.

The air leaving the coolers B, by means of the baflles I25, I26 and the outside wall of the casing, is directed inwardly through the next bank of coolers indicated by the letter C. Finally the air moving into the interior of the tower through the bank C of coolers is discharged outwardly through the bank D, suitable baffles I21 and I28 being provided to aid this. From the bank D of coolers the air passes outwardly through the spray eliminators I29 into the atmosphere.

The liquid to be cooled is supplied through pipe I30. A portion of this passes through the coils or pipes of the coolers and another portion is distributed over the top pipes and drops from pipe to pipe to effect the evaporative cooling.

As shown, above the top bank D of coolers, is a liquid header pipe I3I provided with nozzles I32 delivering liquid into the top channels or troughs I03. The liquid then passes through the slot I04 in'the header and falls onto the pipes and fins of the coolers, thus forming a liquid curtain that is interrupted periodically in its fall. From their lower portions the coolers D .discharge into the upper channels of the next bank C of coolers, suitable deflecting plates I 33 being provided for this purpose. The evaporative water passes downwardly over the coolers C and is collected in the receptacles I34.

As stated, the header I36 is supplied from pipe I30, a suitable valve I35 being provided to control the flow. For the liquid supplied to the interior of the pipes or the coolers, a header I36 is employed which may be connected through pipe I31 to the supply pipe I30. Valve I 38 is provided to regulate the flow. As clearly shown in Fig. 2, the header I26 is connected to the upper part of the coil of each cooler by a connection I39. Each of the coils in the coolers of bank D is connectedto the coil in the next lower bank C by a pipe connection M0. Each of the coils of the coolers C has a discharge pipe I for delivering the cooled liquid into the receptacles l34. From the foreand for the coils there is a header I! connected to the coils in the same manner as described for bank D. Liquid to be cooled is supplied through pipe M which is connected to'header M2 by pipe Mt having a valve Ml therein and to header Mt by'a pipe I43 having a valve Mt therein.

The evaporative water supplied from header M2 passes downwardly over the banks B and A of the coolers, being interrupted periodically in its fall, and is collected in receptacles its provided with suitable partitions ltd to prevent bypassing air around the bottoms of coolers A. The other portion of water supplied to the coils of coolers B is delivered by connections Hi to the corresponding cooler in the next lower bank and to the cooler A shown at the left of Fig. 1, the

movement of air is transversely inwardly through then through outlet pipe IE2 is delivered into the this cooler and the cooler is supported so that, as

a whole, it is inclined toward the right, or direction'of flow.

Any suitable means may be employed for supporting the coolers. Thus as shown, the header Wt may be fastened to corner walls I53 by angles wt. These are shown in Fig. 3, but are omitted from Fig. 1 to avoid confusion. It will be noted that there are two supplies of liquid to be cooled, one through pipe I39 and the other through pipe 5. These supplies may be at the same or different temperatures. For instance, in one use of this tower, water at 85 F. is supplied through pipe I30. The discharge from the re-,

ceptacle' I34 through pipe I55 is at a tempera ture of 81 F. For the lower banks B and A of coolers the water was supplied at 75 F. and is discharged through Pipe I56 from receptacle I09 at a temperature of 71 F.

In this particular instance, the air supplied through the opening ill in the casing had a wet bulb temperature of 616 F. When it left the bank -B of coolersits wet bulb temperature was 72" F.

and when discharged from bank D its wet bulb temperature was 79 F.

single tower or a larger number oi superposed towers might be employed.

This application is a division of my application Serial No. 117,996, filed December 28, 1936.

Having now described the invention, what is claimed as new and desired to'be secured by Letters Patent is:

1. In a cooling apparatus for water, a plurality of superposed. evaporative coolers, each cooler comprising vertically spaced pipes, means to circulate a portion of the water to be cooled successively through. the pipes of an upper cooler, andthrough the pipes of an adjacent lower cooler,

means to distribute another portion of said water to be cooled successively over the pipes of said upper cooler and over the pipes of said adjacent lower cooler, means to pass a stream of air successively over the pipes of said lower cooler and over the pipes of said upper cooler, and common means to collect said portions of water.-

2. Cooling apparatus for liquids comprising a casing, heat-exchange means comprising vertically spaced elements within the casing, means for circulating a liquid through interior passages in said elements to move the'liquid progressively in a general downward direction, means to move a stream of air in a generally upward direction over the exterior surfaces of said heat-exchange means, baille means for deflecting said air stream alternately back and forth through'superposed groups of said heat-exchange means as the air moves upwards, means for distributing water over said heat-exchange means adjacent the top thereof, and meansfor periodically redistributing the water as it flows downwards, said redistribution' taking place at locations of reversal of direction of air flow over said heat-exchange means.

3. Cooling apparatus for liquids comprising a casing, heat-exchange means comprising vertically spaced pipes within the casing, means for circulating a liquid progressively downward through said pipes, means to move a stream of air in a generally upward direction over the exterior surfaces of said heat-exchange means,

bafiie means for deflecting said air stream alter-- nately back and forth through superposed groups of said heat-exchange means as the air moves and means for periodically redistributing the water as it flows downwards, said redistribution taking place at locations of reversal of direction 0 of air flow over said heat-exchange means.

STEWART C. COEY. 

